API Overview

The Lezu API lets you manage localization from your own applications, scripts, CI jobs, and admin tools.

Base URL:

https://api.lezu.app

Most API routes live under /v1.

Authentication

Programmatic clients use API keys:

Authorization: ApiKey lez_...

Browser sessions are available for Lezu apps and dashboards.

Response Format

Successful responses use a consistent envelope:

{
  "data": {},
  "meta": {}
}

Errors use:

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Request validation failed",
    "details": {}
  }
}

Main API Areas

Area	What it does
Auth	Sign up, sign in, sessions, current user, and API keys.
I18n	Projects, imported values, releases, and bundles.
Translate	One-off, bulk, multilingual, and async translation jobs.
Usage	Translation unit summaries and usage reporting.
Billing	Credits, plans, and checkout sessions.
Dashboard	Summary data for the Lezu dashboard experience.

Typical API Flow

1. Create or sign in to a Lezu account.
2. Create an API key with the scopes your integration needs.
3. Create a project.
4. Import source content.
5. Estimate or run translation.
6. Publish a release.
7. Fetch bundles from your app.

Project settings include translationTonePreset for built-in voices such as standard, SaaS product, technical, support, marketing, kids, and formal. Use translationToneCustomInstructions with the custom preset when a project needs its own voice guidance; Lezu passes that project context into AI translations.

For the full list of routes, see the Endpoint Reference. For TypeScript integrations, see API Contracts.